const a = parseInt("a");
const b = a;
console.log(`a = ${a}, b = ${b}`); // a = NaN, b = NaN
console.log(`a == b: ${a == b}`); // a == b: false
console.log(`isNaN(a): ${isNaN(a)}`); // isNaN(a): true
console.log(`a !== a: ${a !== a}`); // a !== a: true
